Chapter 6.3, Problem 17PP

Interpretation Introduction

Interpretation: The krypton from the given figure needs to be identified.

  

Concept introduction: A periodic table consists of groups and periods. The horizontal rows are termed as groups and the vertical rows are termed as periods. The elements with similar properties are placed together in a group.

Answer to Problem 17PP

Atom B is krypton because the size of Krypton lies between the size of He and Rn.

Explanation of Solution

On moving down a group, the number of energy levels increases. The increase in energy levels is due to the increase in the number of electrons as well as the addition of new shells around the nucleus. So, the size of the element also increases down the group due to the screening effect.

Conclusion

Thus, the atom B is Krypton.